Remediação eletrocinética de solo carbonífero poluído com petróleo

Abstract

This work was carried out with the purpose of observing the application of electrokinetic treatment and behavior of its phenomena (electrolysis, electro-osmosis, electromigration and electrophoresis) in the decontamination of carbonaceous soils contaminated by exogenous components. To test this, a series of experiments was performed to determine the best volume treatment thus modifying electrokinetic cells used. The experiments were performed in cells with different internal volumes ranging from 0.2 L, 1.5 L and 3.0 L, thus varying the volume to better comprotar samples thus favoring the development of a cell with better performance for the experiment. In both experiments developed soil was contaminated with different concentrations of crude oil from the formation Umburana ranging from 500 mg/L to 2500 mg/L, thus constituting the contaminated sediment coal matrix. For configuration of the sample used is an amount of sediment weighing between 0.05 kg, 0.8 kg and 1.5 kg of coal sedimentary rock macerated, processing was done so that is reached one granulometric fraction of 35 # (mesh ) or 0.5 mm. A series of experiments will be discussed in three main units; Preliminary experiments, intermediate and final in which consolidated a methodology for Electrokinetic Remediation of Soils (RES) with higher yield due to constructive interference of s own utliada cell. The utlizados electrodes for remediation were Dimensionally Stable Anode (DSA) of ruthenium-titanium-oxide (Ti/Ru0,34Ti0,66O2) and electrodes of graphite carbon (graphite sp2) applying different currents eletricas. The removal of organic compounds was monitored by Total Organic Carbon (TOC), Zeta potential (ζ) and spectrophotometric measurements (UV-Visible). They were also made Hydrogen ion-potential measurement (pH), conductivity (mS/cm) and the volume of vaporization of the electrolyte used (Na2SO4). The results indicated decontamination of the medium between 50% to 80% with low cost 0.04 Real/kWh, with a good percentage for removal of oil derivatives on the ground. The tests lasted between 72 h to 480 h and checked for removal of pollutants in the cathodic and anodic compartment, with possible load heavy metals. The zeta potential indicated that the organic compounds are transported due to electromigration and electro-osmosis phenomena, and confirms that the particle size varies during the decontamination time, thus forming "cluster" of electrically charged particles that mostly holds negative charge. Electrolysis of electrolyte favors the formation of a pH gradient, thus forming an acid/base face detected by analysis of the electrolyte in the reservoirs, it is enabling an increase in mobility of soil contaminants to the reservoirs. The residual effluent contaminated with oil, has also been treated with anodic oxidation utlizando of electrode the dimond doped with boron (DDB) and current densities of 20 and 60 mA/cm2, the final levels of decontamination achieved by coupled treatment were 80% in the residual effluent defining a high level of decontamination.